PTL 1 discloses a technique for detecting a spatial position of a moving object. PTL 2 discloses a mobile robot that calculates the self-position based on markers. In the technique described in PTL 2, positional information and identification information regarding markers placed at predetermined locations are stored in association with map information, and the mobile robot calculates its self-position using this map information.
PTL 3 discloses a system that supports picking operations based on identifiers attached on shelves in a warehouse or similar place. PTL 4 discloses a technique by which two or more markers are captured in an image during imaging, and three or more radiation images having an overlapped area are combined together.